1. Field of the Invention
The present invention relates to a helmet display in which a display is disposed on the jaw of the helmet and a driver wearing the helmet sees a virtual image behind a reflector such as the shield of the helmet or a combiner which reflects the image of the display into the driver's eyes.
2. Prior Art
There has been a conventional display called a head-up display used in an automotive vehicle. A display is disposed on the dashboard of a vehicle and the image of the display is reflected by a reflector disposed on the windshield into a driver's eyes, so that the driver sees the virtual image of the display behind the reflector. The image appears on the windshield through which the driver sees the outside of the vehicle while driving. This is advantageous in that the driver only needs to slightly move his eyes in order to look at the image. FIG. 7 shows this type of head-up display which is referred to as a helmet display and is built in a helmet for a motorcycle driver. The helmet display is provided with a display 13 on the interior of a jaw 2 of the helmet 1. The display 13 is so positioned that the display 13 projects its image upwardly towards the shield 4. The shield 4 reflects the image into the driver's eyes. The driver sees a virtual image Xo of the display behind the shield 4.
FIG. 8 shows another conventional helmet display. The image of the display is not reflected by the shield 4 but is reflected by a combiner 15 mounted on the upper portion of the jaw 2 of the helmet 1. The light reflected by the combiner 15 enters the driver's eyes. The driver sees a virtual image Xo the display behind the combiner 15. The display 23 includes a liquid crystal 25 with a back light 24 and the image of the display 23 is enlarged by a lens 26. Thus, the driver sees the virtual image Xo as being a long way from the driver. The conventional helmet displays in FIGS. 7 and 8 have advantages similar to those of the headup display used for conventional four-wheel vehicles. The display moves with the driver's face, so that the information such as vehicle speed and engine speed is always displayed at an optimum position for the driver to see.
However, the aforementioned helmet displays have a single flat screen for displaying the image and therefore the reflective surface of the reflector must also be flat so that the image seen by the driver is not distorted. Thus, the shield 4 in FIG. 7 must have a flat surface. This requirement of a flat surface may result in an ugly or uncommon appearance of the helmet. Meanwhile, the helmet in FIG. 8 needs no flat surface of the shield 4 since the helmet has a combiner as a reflector. However, the combiner is located very close to the driver's face and causes inconvenience if the driver wears glasses.